Precipitation behavior and high strain rate superplasticity in a novel fine-grained aluminum based alloy
Precipitation behavior and high strain rate superplasticity in a novel fine-grained aluminum based alloy
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新型细晶粒铝合金的析出行为和高应变率超塑性
DOI：
10.1016/j.msea.2019.05.099
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
N. Tabachkova
中科院分区：
文献类型：
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作者：
A. Mikhaylovskaya;A. Kishchik;A. Kotov;O. Rofman;N. Tabachkova
开发具有上级力学性能和高应变速率超塑性的铝合金是推动超塑性吹塑成形技术应用的重要前提。研究了Ce和Fe对超塑性Al-4.8%Mg-0.6%Mn-0.15%Cr（AA 5083型）合金显微组织参数和拉伸性能的影响。所研究的合金具有双峰粒度分布，具有粗大的结晶源夹杂物和细小的二次析出物。粗颗粒和细颗粒都导致晶粒细化。粗铈，铁，锰丰富的金属间化合物颗粒的结晶起源提供了证据的颗粒刺激成核效应。在低温均匀化后，半共格的Mn富集致密形状的弥散体具有Ashby-Brown对比度、准晶结构和平均尺寸为38 nm，并表现出较强的Zener钉扎效应。建议的形变热处理导致再结晶板的晶粒尺寸为4 μm，极限抗拉强度为340 MPa。在1 × 10− 2 ~ 1 × 10− 1 s − 1应变速率范围内的超塑性变形行为以及应变引起的晶粒结构和力学性能的变化。
The development of aluminum alloys with superior mechanical properties and high strain rate superplasticity is an important prerequisite for advancing applications of superplastic blow-forming technology. This study focuses on the effect of Ce and Fe additions on the microstructural parameters and tensile properties of a superplastic Al-4.8%Mg-0.6%Mn-0.15%Cr (AA5083-type) alloy. The studied alloy exhibits a bimodal particle size distribution with coarse crystallization origin inclusions and fine secondary precipitates. Both the coarse and fine particles lead to grain refinement. The coarse Ce-, Fe-, and Mn-rich intermetallic particles of crystallization origin provide evidence of a particle-stimulated nucleation effect. The semi-coherent Mn-enriched compact-shaped dispersoids with an Ashby-Brown contrast, a quasicrystalline structure, and a mean size of 38 nm are precipitated after low-temperature homogenization and exhibit a strong Zener pinning effect. The proposed thermomechanical treatment results in the development of a grain size of 4 μm and an ultimate tensile strength of 340 MPa in the recrystallized sheet. The superplastic deformation behavior in a strain rate range of 1 × 10−2to 1 × 10−1s−1and the associated strain-induced changes in the grain structure and mechanical properties of the developed alloy are presented and discussed.